Tool holders of the general class to which the invention relates are disclosed in Nickless Pat. No. 2,719,722; Botimer Pat. No. 3,512,793; and Koch Pat. No. 3,829,109. Another tool holder construction of the general class to which the invention relates is disclosed in Botimer copending application Ser. No. 461,141, filed Jan. 26, 1983. Such application also discloses a clutch mechanism which may be utilized by the present construction during the coupling and uncoupling of a tool to and from a rotating spindle without requiring the machine tool operator to touch either the spindle, the tool, or the tool holder.
Although the devices disclosed in the aforementioned patents and application enable a tool to be coupled to and uncoupled from a rotating spindle, the tools heretofore used in such operations have been fairly light in size. That is, tools such as drills and taps, for example, are sufficiently light weight that the manual coupling and uncoupling during spindle rotation is not precluded. However, heavier tools, such as end mills, shell mills, boring bars, and the like must be of such strength and rigidity as to be able to compensate for side thrusts. Such tools, therefore, have substantial weight and, consequently, greater inertia which sometimes makes it difficult, if not impossible, to enable tool and spindle coupling and uncoupling to be performed manually.
In those instances in which the coupling and uncoupling of tools to and from a rotary spindle occurs without stopping the spindle, it is inevitable that wear or deformation, or both, occurs between those parts of the spindle and tool which initially engage one another during the fitting of the tool to the spindle. The greater the weight of the tool and the greater the speed of rotation of the spindle, the greater the wear and deformation of such parts. The clutch mechanism disclosed in the above identified application enables relatively heavy tools to be fitted to a spindle which rotates faster than one adapted for use in the manual operation. The faster rotation of a spindle during tool change operations, however, may result in accelerated wear or deformation, or both, of those parts of the tool support and spindle assembly which first engage one another.
A primary object of the present invention, therefore, is to provide a tool support assembly adapted to be coupled and uncoupled to and from a continuously rotating spindle assembly and wherein wear and deformation of the respective parts are minimized. Another object of the invention is to provide for the replacement of such parts following their wear or deformation and without necessitating replacement of other components of the spindle or tool support assemblies.
A further object of the invention is to provide a tool support assembly which can be coupled to and uncoupled from a rotating spindle, and which enables substantial side thrust loads to be accommodated.